• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.545-552
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• 2017

Increasing concern is being given to the association between risk of cancer and exposure to low-dose bisphenol A (BPA), especially in young-aged population. In this study, we investigated the effects of repeated oral treatment of low to high dose BPA in juvenile Sprague-Dawley rats. Exposing juvenile rats to BPA (0, 0.5, 5, 50, and 250 mg/kg oral gavage) from post-natal day 9 for 90 days resulted in higher food intakes and increased body weights in biphasic dose-effect relationship. Male mammary glands were atrophied at high dose, which coincided with sexual pre-maturation of females. Notably, proliferative changes with altered cell foci and focal inflammation were observed around bile ducts in the liver of all BPA-dosed groups in males, which achieved statistical significance from 0.5 mg/kg (ANOVA, Dunnett's test, p<0.05). Toxicokinetic analysis revealed that systemic exposure to BPA was greater at early age (e.g., 210-fold in $C_{max}$, and 26-fold in AUC at 50 mg/kg in male on day 1 over day 90) and in females (e.g., 4-fold in $C_{max}$ and 1.6-fold in AUC at 50 mg/kg vs. male on day 1), which might have stemmed from either age- or gender-dependent differences in metabolic capacity. These results may serve as evidence for the association between risk of cancer and exposure to low-dose BPA, especially in young children, as well as for varying toxicity of xenobiotics in different age and gender groups.

• Journal of Preventive Medicine and Public Health
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• v.12 no.1
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• pp.70-78
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• 1979

This study was carried out for the evaluation on the sociomedical characteristics of 1,580 cases who had recieved vasectomy and laparoscopic sterilization at the Busan Family Planning Clinic from January 1975 to December 1973. The results obtained were as follows: 1. In age distribution, the most predominant age group consited of 30.34 years as 44.7%. In regional distribution, the most predominant region was Youngdo Ku in the vasectomy group and Dong Ku in the laparoscopic sterilization group. 2. The educational level showed that the high school graduates(49.2%) in the vasectomy group and the primary school graduates(47.0%) in the laparoscopic sterilization group were the highest each other. 3. The most predominant experienced contraceptive method before accepted permanant sterilization operation was oral pills and non-experienced contraceptive method group was 54.1% of the total. 4. By the span of marital life before accepted permanant sterilization operation, the 5-9 years group was the highest. 5. The average number of living children per family was 2.54 in the vasectomy group and 3.0 in the laparoscopic sterilization group. 6. The average frequency of pregnancy per case was 2 in the vasectomy group and 3 in the laparoscopic sterilization group and the most predominant frequency of induces abortion was 1 per case. 7. The most predominant motive of accepting the sterilization operation were family planning education at the reserve forces training in the vasectomy group and at the mother's club in the laparoscopic sterilization group. 8. By the residing status of the cases, rented room was the highest as 69.4%.

• The Journal of the Korea Contents Association
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• v.20 no.8
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• pp.298-314
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• 2020

This study was conducted for the purpose of empirically analyzing the effects of the adolescents' relationships with major adults as the protection factors for their game addiction. Specifically, the discriminatory effects of adolescents' relationships with their parents, school teacher, and educational institute teachers on game addiction among elementary, middle, and high school students were compared. Analyzing the data from "2019 Korean Children and Youth Happiness Index" (N=7,454), it was found that adult relationships are significant factors explaining the level of game addiction even after controlling the influence of adolescents' demographic and social characteristics, game use behavior, and friend relationship factors. In the case of elementary school students, the relationship with their mothers reduces the risk of game addiction, while for middle and high school students, the relationship with fathers acts as a protection factor for game addiction. Meanwhile, the protection effects of the relationship between teenagers and school teachers on game addiction was found only in middle school students, and contrary to expectations, the relationship with the educational institute teacher did not have a significant impact on the game addiction of teenagers. Based on the above major research results, this study discussed on the development of programs and policies for the prevention and intervention of youth game addiction and provided suggestions for the follow-up research in the future.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.2
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• pp.256-265
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• 1997

Objectives：The purpose of this study was to investigate the characteristics and differences of brain function in pervasive developmental disorder and developmental language disorder. Method：The subjects were composed of 14 cases of pervasive developmental disorder and 13 cases developmental language disorder. They were investigated by technitium-99m-EDC SPECT. All SPECT were visually assessed by two nuclear medicine specialists, and then quantified by region of interest including temporal, parietal cortex, thalamus, basal ganglia and cerebellum. Result：In both groups, cerebral blood flow was decreased in the temporal, parietal cortex, basal ganglia, thalamus, cerebellum by visual assessment. There was no significant difference between the 2 groups by quantitative and qualitative assessment. Conclusion：These results suggest that pervasive developmental disorder and developmental language disorder are caused by defects in the interneural connection and that both disorders are spectrum disorders.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.677-683
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• 2008

The purpose of study was to compare the prevalences of severe early childhood caries(S-ECC) using two different diagnostic criteria. The subjects of this study included 401 preschool children from 36 to 71 months of the randomly selected seven nurseries in Iksan city. Severe early childhood caries was defined as (1) 1 or more cavitated, missing (due to caries), or filled smooth surfaces in primary maxillary anterior teeth or (2) a decayed, missing, or filled score of ${\geq}$4 (age 3), ${\geq}$5 (age 4), or ${\geq}$6 (age 5) surfaces. The prevalence determined by maxillary anterior caries and the prevalence determined by dmfs were 26.7%, 28.9% in 3 years, 32.4%, 30.4% in 4 years, 39.4%, 41.3% in 5 years, and 35.4%, 35.9% in all, respectively. The results suggest that the two diagnostic criteria of the severe early childhood caries yield almost the same results.

• School Mathematics
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• v.12 no.3
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• pp.353-370
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• 2010

The purpose of this study was threefold: (1) to select the components of spatial ability that could be associated with the implementation of a polycube task, embody the selected components of spatial ability as learning elements and develop the prototype of polycube teaching-learning materials applicable to gifted education, (2) to make a close analysis of the development process of the teaching-learning materials to ensure the applicability of the prototype, (3) to give some suggestions on the development of teaching-learning materials geared toward mathematically gifted classes. The findings of the study were as follows: As for the first purpose of the study, relevant literature was reviewed to make an accurate definition of spatial ability, on which there wasn't yet any clear-cut explanation, and to find out what made up spatial ability. After 13 components of spatial ability that were linked to a polycube task were selected, the prototype of teaching-learning materials for gifted education in mathematics was developed by including nine components in consideration of children's grade and level. Concerning the second purpose of the study, materials for teachers and students were separately developed based on the prototype, and the materials were modified and finalized in light of when selected students exerted their spatial ability well or didn't in case of utilizing the developed materials in class. And then the materials were finalized after being finetuned two times by regulating the learning type, sequence and degree of learning difficulty. Regarding the third purpose of the study, the polycube task performed in this study might not be generalizable, but there are seven suggestions on the development process of teaching-learning materials.

• Parasites, Hosts and Diseases
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• v.53 no.6
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• pp.771-775
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• 2015

In order to determine the status of Enterobius vermicularis infection among schoolchildren in suburban areas of Myanmar, 761 primary schoolchildren in 3 different townships around Yangon City were subjected to a survey using cello-tape anal swabs. The subjected schoolchildren were 383 boys and 378 girls who were 5-7 years of age. Only 1 anal swab was obtained from each child. The overall egg positive rate of E. vermicularis was 47.2% (359 positives), and sex difference was not remarkable (48.6% in boys and 45.8% in girls). However, the positive rate was the highest in South Dagon (54.6%) followed by Hlaing Thayar (43.8%) and North Dagon (34.8%). This difference was highly correlated with the living standards of the people in each township. Nucleotide sequence of the 5S rDNA from the eggs on the cello-tape (2 children) revealed 99.7% identity with that of E. vermicularis reported in GenBank. The results indicated that E. vermicularis infection is highly prevalent among primary schoolchildren around Yangon, Myanmar.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.93-98
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• 2008

Rare cases of IgG associated mesangial glomerulonephritis(IgG GN) defined by exclusive or predominant mesangial IgG deposits were reported first by Sato et al.(1993). and subsequently 10 pediatric cases were reported by Yoshikawa et al.(1994). Previous reports suggested that the prognosis of IgG GN is relatively benign course but recent report suggested that prognosis of IgG GN is highly variable. Also the recurrence of IgG GN in a renal transplant was reported by Fakhouri et al. (2002). Such a recurrence highlights the specificity of this type of glomerulonephritis. We experienced two pediatric cases of IgG GN proven by renal biopsy. Case 1. 4-year-old girl with nephrotic syndrome admitted because of general edema. The patient's urinalysis showed proteinuria and microscopic hematuria. Renal biopsy was performed because of relapsed nephritic syndrome. Light microscopic finding was nonspecific with almost normal histology. Immunofluorescent findings showed diffuse segmental IgG(+) and IgM(+) deposits in the capillary walls, and focal segmental spotty C4(trace), C1q(trace) deposits. Electron microscopic findings showed focal portion of mesangial electron dense deposits without mesangial widening. Case 2. 11-year-old girl admitted for evaluation of microsopic hematuria detected through mass school urinary screening program. Renal biopsy was performed for exact diagnosis. Immunofluorescent findings showed focal segmental IgG(+), IgM(+/-) and C3(+/-) deposits. Electron microscopic findings showed focal portion of mesangial electron dense deposits without mesangial widening.

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.204-210
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• 2003

Membranoproliferative glomerulonephritis type II(MPGN II), also called dense deposit disease, was first described by Berger and Galle in 1963. The diagnosis of MPGN II is based on electron-microscopic finding of an intensely electron-dense substance which replaces the lamina densa of the glomerular basement membrane. Although the etiology and pathogenesis of MPGN II are unknown, it frequently progresses to end-stage renal failure. Typically in MPGN II, hypocomplementemia due to activation of the alternative complement pathway is present. In addition, the association of MPGN II with partial lipodystrophy and complement abnormalities is well documented. The relationship between these associated features and the patient's renal functional outcome is not clear. With respect to the therapy for MPGN II, an alternate-day prednisolone regimen was shown to be effective. Various treatment modalities, including immunosuppression with corticosteroids, cytotoxic drugs and cyclosporin A, anticoagulants and antiplatelet therapies are used, either alone or in combination, with varying degrees of success. The purpose of this paper is to present a case of MPGN II from a 7 years old girl with paroxysmal supraventricular tachycardia(PSVT).

• Journal of Dairy Science and Biotechnology
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• v.37 no.1
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• pp.1-14
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• 2019

In general, milk is a nutritious food and is very helpful in improving and maintaining a person's health. However, over the past 30 years, a number of studies have reported the presence of Aflatoxin M1 in milk and milk products worldwide. The contamination with Aflatoxin M1 in milk and dairy products has become an important issue all over the world. The presence of the mycotoxin in these products was a major concern particularly among children and infants, who are more sensitive than adults. This study reviewed recent data to summarize the current status of Aflatoxin M1 in milk and dairy products produced in various regions around the world, related regulations, reduction strategies, detection methods, and future research tasks. Strict regulation and superior milk-handling techniques are essential to minimize Aflatoxin M1 contamination in milk and dairy products using ever-evolving analytical techniques. Furthermore, education should be imparted to ensure that Aflatoxin M1 that may exist in milk and dairy products and its effects on human health are made aware of.